// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CC_TILES_TILING_SET_RASTER_QUEUE_REQUIRED_H_
#define CC_TILES_TILING_SET_RASTER_QUEUE_REQUIRED_H_

#include "cc/base/cc_export.h"
#include "cc/tiles/picture_layer_tiling_set.h"
#include "cc/tiles/raster_tile_priority_queue.h"
#include "cc/tiles/tile.h"

namespace cc {

// This queue only returns tiles that are required for either activation or
// draw, as specified by RasterTilePriorityQueue::Type passed in the
// constructor.
class CC_EXPORT TilingSetRasterQueueRequired {
public:
    TilingSetRasterQueueRequired(PictureLayerTilingSet* tiling_set,
        RasterTilePriorityQueue::Type type);
    ~TilingSetRasterQueueRequired();

    const PrioritizedTile& Top() const;
    void Pop();
    bool IsEmpty() const;

private:
    // This iterator will return all tiles that are in the NOW bin on the given
    // tiling. The queue can then use these tiles and further filter them based on
    // whether they are required or not.
    class TilingIterator {
    public:
        TilingIterator();
        explicit TilingIterator(PictureLayerTiling* tiling,
            TilingData* tiling_data,
            const gfx::Rect& rect);
        ~TilingIterator();

        bool done() const { return !current_tile_.tile(); }
        const PrioritizedTile& operator*() const { return current_tile_; }
        TilingIterator& operator++();

    private:
        PictureLayerTiling* tiling_;
        TilingData* tiling_data_;

        PrioritizedTile current_tile_;
        TilingData::Iterator visible_iterator_;
    };

    bool IsTileRequired(const PrioritizedTile& prioritized_tile) const;

    TilingIterator iterator_;
    RasterTilePriorityQueue::Type type_;
};

} // namespace cc

#endif // CC_TILES_TILING_SET_RASTER_QUEUE_REQUIRED_H_
